It slides around constantly. I can even lift it 3/4 inch upwards and see the pipes underneath in their little holes. I have felt under there with my fingers but I don't know what I'm feeling for to try and tighten it. What is the mechanism that tightens it to my sink, and how do I go about fixing it?
you need to get a flash light and get inside the cabinet...just be care full because any loose rust will fall into your eyes...there is probably 1 large nut or 2 smaller nuts they need to be tightened up...its not uncomon on old faucetts for it to rust away and not even be there any more...you may need a special wrench (basin wrench) to get up there
two screws, one on each knob. Untighten them, and take the knobs off. get a crescent wrench, and tighten the brass nuts under neath where the knobs were. If that didn't get it, you have to go under the sink and take a look, and jus tstart tightening everything
i know you know how to tighten it underneath, it's just a loose nut, but as an addition put water based epoxy between the faucet and the basin to have better hold. do not use the faucet overnight for best results.
Put putty around the base of the tap on the drainer, then using a basin wrench, and someone to hold the faucet, you have to get underneath, and tighten the brass nut attached to the faucet. The nut may also be a plastic type.there is also a fitting called a "top Hat " that can be fitted between the Faucet and the nut, this will stop your faucet from ever coming loose again. To fit this, you will need to disconnect the Faucet from the pipe and fit it around the stem of the faucet, then connect the pipe and brass nut, and tighten until the faucet is immovable. Try not too overtighten the Faucet to the nut or you will destroy the fibre washer fitted in side the back nut.
since your faucet has come loose to the point you can lift it, its not a matter of simply tightening the nuts. you will need to use plumbers putty to seal the deck of the faucet before tightening it down. if you skip this small step, you will have water infiltration into the cabinet. after resealing with putty, simply use a basin wrench and torque down the two plastic or brass metasl nuts. this shouild fix your issue
